Method of coupling the components of a molding retainer

ABSTRACT

A molding retainer having an apertured molding engaging cross plate and an attaching bolt secured to the cross plate includes a wire spring arm for biasing the cross plate into a molding engaging attitude. The wire spring arm is clamped against the underside of the cross plate by a flange on the bolt shank disposed beneath the cross plate and spaced from the head of the bolt. The bolt is nonrotatably locked to the cross plate through the aggressive engagement of the walls of the polygonal aperture in the cross plate by a bolt shank section of corresponding polygonal configuration which shank section is formed by the deformation and axial flow of the bolt material incident to the forming of the bolt head, which forming is carried out subsequent to the seating of the bolt in the cross plate aperture. An improved method of joining the cross plate and bolt components of a molding retainer is also disclosed.

United States Patent [191 Becker [4 1 Dec. 9, 1975 METHOD OF COUPLINGTHE COMPONENTS OF A MOLDING RETAINER [75] Inventor: Charles HenryBecker, Braintree,

Mass.

[73] Assignee: TRW Inc., Cleveland, Ohio [22] Filed: Nov. 7, 1974 [21]Appl. No.: 521,823

Related U.S. Application Data [62] Division of Ser. No. 281,697, Aug.18, 1972, Pat. No.

[52] U.S. Cl. 29/509; 29/522; 72/119 [51] Int. Cl. B21D 39/00; B23P11/00 [58] Field of Search 29/509, 522; 72/118, 119, 72/77; 52/718;24/73 BC; 85/9 R [56] References Cited UNITED STATES PATENTS 1,814,7037/1941 Johnson 29/509 2,531,351 11/1950 Churchill 24/73 BC 2,654,27210/1953 Warren 29/509 UX 2,695,434 ll/l954 Bedford 24/73 BC 2,709,2865/1955 Bedford 1 1 24/73 BC 2,713,186 7/1955 Borowsky 24/73 BC 2,761,2099/1956 Fisher 29/509 3,011,234 12/1961 Fiddler 24/73 BC 3,362,449 1/1968Borwick et a1 1 29/522 X 3,461,637 8/1969 .lansson 52/718 PrimaryExaminer-Charlie T. Moon Attorney, Agent, or Firm lames R. OConnor [57]ABSTRACT section of corresponding polygonal configuration which shanksection is formed by the deformation and axial flow of the bolt materialincident to the forming of the bolt head, which forming is carried outsubsequent to the seating of the bolt in the cross plate aperture. Animproved method of joining the cross plate and bolt components of amolding retainer is also disclosed.

2 Claims, 5 Drawing Figures Patent Dec. 9 1975 U 3 s 2 4 x Q 01 2 i 3 I.X. J m J 8 w Q m w w. I

METHOD OF COUPLING THE COMPONENTS OF A MOLDING RETAINER This is adivision of application Ser. NO. 281,697, filed Aug. 18. 1972, now U.S.Pat. No. 3,863,300.

BACKGROUND OF THE INVENTION 1. Field of the Invention The inventionrelates to molding retainers of the type found in U.S. Art Class 24,Subclass 73, entitled Fasteners Combined and particularly to retainersof the subclass having a fastener member which is not integral with themolding engaging cross plate and, with reference to the preferredembodiment, a nonintegral, retainer biasing, wire spring arm.

2. Description of the Prior Art The prior art is best characterized byU.S. Pat. No. 2,695,435 (W. A. Bedford, Jr.), U.S. Pat. No. 2,852,828(D. C. Hamman), U.S. Pat. No. 2,709,285 (W. A. Bedford, Jr.), and U.S.Pat. No. 3,011,234 (T. E. Fiddler). The patents to Bedford, Jr., U.S.Pat. No. 2,695,435 and Hamman U.S. Pat. No. 2,852,828 are characterizedby a retainer having a spring arm integral with the molding engagingcross plate. Bedford, Jr., US. Pat. No. 2,709,286 points out theprincipal deficiency in these integral constructions, to wit, that thestrengthening of the cross plate through heat treatment, particularlyfor larger size molding retainers, results in embrittlement in theretainer biasing arm to the extent that the arm frequently breaks inlieu of flexing when placed in tension in a molding assembly. Bedford,Jr., U.S. Pat. No. 2,709,286 corrected this deficiency by employing aseparate wire spring arm joined to an edge of the cross plate by atongue formed integrally with the cross plate and curled over one end ofthe wire spring arm. This construction represented a marked improvementin the art and parts manufactured according to the teachings of thepatent have enjoyed considerable success in the marketplace. Fiddlersought to and did provide a still further improvement over the teachingsof Bedford, Jr., U.S. Pat. No. 2,709,286 in certain aspects and theFiddler construction has likewise enjoyed commercial success. Fiddlerconnected a separate wire spring arm to the bolt of the retainercombination by providing a cross slot in the bolt head and seating aportion of the wire arm in the slot and peening the head materialadjacent the slot over the wire arm section seated therein. As thepatent clearly states, the advantage gained was the ability to utilize aspring arm of true specified temper in that heat treatment of the crossplate could be completed prior to spring arm attachment. A furtheradvantage according to Fiddler is that the spring arm attachment and thecoupling of the bolt to the cross plate can be carried out in a singlemanufacturing operation. The present invention is seen to provide astill further improvement in the art relative to spring arm attachmentin a molding retainer combination as will become evident from thedetailed description of a preferred embodiment which followshereinafter.

Regardless of the type of spring arm connection employed. however, allof the retainer constructions disclosed in the aforementioned patentsare characterized by the fact that the cross plate is provided with apolygonally shaped aperture, i.e. one which is square, rectangular,hexagonal, etc., and the bolt shank beneath the head is manufactured,i.e. preformed prior to attachment, with a correspondingly shapedpolygonal section 2 to inhibit relative rotation between the bolt andcross plate subsequent to the coupling of those components. While Hammandoes not disclose ajoint which inhibits relative axial movement betweenthe bolt and cross plate, both Bedford, Jr., patents and the Fiddlerpatent depict constructions wherein the corners of the polygonal boltshank section are staked over the underside of the cross plate to thuscooperate with the bolt head in fixing those components against relativeaxial movement and/or separation. Since the material of the bolt shankis in effect sheared or torn incident to the staking operation and sinceonly a minimal amount of metal is available at the corners of thepolygonal section for staking over the cross plate, all of the prior artfasteners are considered somewhat deficient in this aspect, i.e. theydisclose a relatively weak fastening of the bolt to the cross platewhich increases the possibility for relative axial movement of thecomponents resulting from a fracturing of the staked connectingelements. The present inventionremedies this deficiency by providing animprovedboltto cross plate coupling which is more effective in resistingboth relative rotation and axial separation of the components and thuscontributes to the art a molding retainer which is more efficient andreliable than those heretofore known.

In another aspect, it is common practice in the art, although theaforementioned patents are not particularly indicative of the practice,to include a sealing element in the overall retainer combination toprovide a moistureproof seal at the opening in a supporting workpiece towhich the retainer and engaged molding are attached, e.g. the body panelof an automobile chassis. Usually the sealing element is in the form ofa soft foam plastic ring which is carried by the bolt shank adjacent theside of the cross plate which confronts the supporting workpiece. Whensuch sealers are combined with the fasteners of the prior art referencesabove mentioned, assembly of the sealer has required an additionalmanufacturing operation subsequent to the coupling of the principalfastening components of the retainer in that post assembly heattreatment in the case of retainers of the Bedford, J r., type would tendto melt and thus destroy a previously assembled sealing ring and in thecase of the Fiddler type retainer the staking operation to fix the boltto the cross plate would destroy or substantially damage a previouslyassembled sealing ring. According to the present invention, the methodof assembling the retainer fastener components, specifically thefastening of the bolt to the cross plate, permits prior installation ofa sealing ring on the bolt shank without any resulting damage to thesealing ring and thereby greatly simplifies the assembly operations andrenders production more economical.

Thus the principal objects of the present invention are to provide animproved molding retainer structure with respect to the coupling of thecross plate biasing spring arm to the retainer, to provide an improvedbolt to cross plate coupling in either a retainer having the overallstructure of the preferred embodiment disclosed or one wherein thespring arm is secured to the cross plate by previously employed couplingmeans, for example, that disclosed in Bedford, Jr., U.S. Pat. No.2,709,286, and to provide an improved method of coupling the componentsof a molding retainer combina tion.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a plan view of a moldingretainer according to a preferred embodiment of the invention assembledwith a fragmentary length of a molding strip;

FIG. 2 depicts the assembly of FIG. 1, as seen in an enlarged crosssection taken on line 22 of FIG. 1, secured to a cross sectional,fragmentary portion of an apertured workpiece and additionally depicts asealing ring disposed about the bolt component of the retainer foreffecting a seal at the workpiece aperture;

FIG. 3 is a perspective view of a preferred embodiment of a moldingretainer according to the invention including a sealing ring assembledwith the bolt component of the retainer;

FIG. 4 is an exploded, perspective view of the components of thepreferred embodiment of the molding retainer prior to assembly of thecomponents; and

FIG. 5 is a fragmentary perspective view of a cutaway portion of themolding retainer depicting details of the bolt, cross plate and springarm connection.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing, there isillustrated a molding retainer combination 2 including generally amolding engaging cross plate 4, a bolt 6 for securing the cross plate toan apertured workpiece, a spring arm 8 for biasing the cross plate intoan effective molding engaging attitude, and a sealing ring 10 carried bythe bolt for effecting a moistureproof seal at one side of a supportingapertured workpiece. The retainer 2 is designed to secure a generallyC-shaped molding 12 having a back portion 14 and longitudinal inturnedflanges l6 defining opposing recesses 18 to a workpiece 20, e.g., anautomobile body panel, having an aperture 22 formed therethrough.

The cross plate 4 has eccentrically arced ends 24 and generally straightside edges 26 extending between its arced ends. The width of the crossplate is less than the distance across the inturned flanges of themolding and its length is greater than said distance. The cross plate isthus adapted to be inserted lengthwise between the molding flanges androtated until its arced ends 24 are seated in the recessed 18 in themolding behind the flanges 16. Once the cross plate is positioned in themolding as aforesaid, spring arm 8 is unwound to the extent necessaryand then released to snap it into one of the molding recesses at alocation substantially spaced from the cross plate and thus exert alocking bias on the retainer (see FIG. 1). The angle of inclination ofthe assembled cross plate relative to the longitudinal axis of themolding will of course vary with the overall width of the molding and itis sufficient for the purposes of this disclosure to state that thedescribed configuration of the cross plate and the biasing action of thespring arm render a given size retainer effective for use over a widerange of molding widths or at spaced locations along a tapering moldingstrip, as will be well understood by those having familiarity with theart. The fastening of the molding and retainer to the workpiece issubsequently accomplished by passing the shank of the bolt 6 through anopening 22 in the workpiece and torquing a nut 60 onto the bolt and upagainst the remote surface of the workpiece. As is clearly depicted inFIG. 6, the tightening of the nut 6a draws the confronting surfaces ofthe molding flanges l6 tightly against the proximate workpiece surfaceand the sealing ring 10 is compressed against the same surface toprovide a moistureproof seal at the workpiece aperture.

The foregoing description is illustrative of the general characteristicsof the retainer and its typical molding engaging and attaching function.The construction of the above mentioned retainer components may bevaried without departing from the scope of the present invention. Thefeatures of the presently preferred embodiment of the retainer and themethod of assembling the components thereof in which novelty is seen toreside are more specifically set forth hereinafter.

With reference particularly to FIG. 4, the reader will observe that ahexagonally shaped aperture 28 is blanked out of the central portion ofthe cross plate 4 and the area of the cross plate surrounding theaperture is embossed to provide a generally circular recess 30 in theunderside thereof. Further, the cross plate is generally peripherallyembossed at 34 to provide a radially extending underside recess 36communicating with the recess 30. The bolt 6 includes a solid,cylindriform, rivetlike shank portion 38, a peripheral flange 40extending radially outwardly from the base of the shank portion 38 anddefining a bearing shoulder 42, and a threaded shank portion 44extending from adjacent the underside of the flange 40 toward theopposite end of the bolt. The diameter of the cylindriform shank portion38 is less than the minimum width of the aperture 28 in the cross plate.The diameter of the bolt measured across the outer peripheral edge offlange 40 is greater than the maximum width of the cross plate aperture28.

Wire spring arm 8 includes a loop 46 at one end thereof traversing anarc of approximately 270, a first relatively straight reach 48 extendingfrom the loop end to an angularly bent bight defining a hinging portion50 and a second relatively straight reach 52 extending from the hingingportion 50 to the opposite end of the spring arm, which end terminatesin a reversely bent (relative to the bend at hinging portion 50) moldingengaging portion 54.

Sealing ring 10 which is formed from a relatively soft foam typesynthetic plastic has a central opening 56 extending therethrough.

Assembly of the component parts of the retainer combination isaccomplished as follows: The sealing ring 10 is first run onto thethreaded shank portion 44 of the bolt until it abuts the underside ofthe flange 40. The bolt and sealing ring assembly is then placed in anappropriate fixture or die and the loop end of the spring arm is placedover the rivetlike shank 38 so that the loop partially circumscribessaid shank and rests on the shoulder 42 defined by flange 40. The crossplate 4 is then placed on the bolt with the rivet shank 38 extendingthrough the cross plate aperture 28 and protruding beyond the upper,embossed surface of the cross plate. The looped end 46 of the spring armthus lies in the re cess 30 and the first reach 48 of the arm lies inthe communicatin g radial recess 36. The rivet shank 38 is then deformedto form bolt head 58 whereby the components are locked together with theshoulder 42 of flange 40 tightly clamping the looped end of the springam against the undersurface of the cross plate defined by the base ofrecess 30. Deformation of the rivet shank 38 is accomplished by aprocess known as orbital heading whereby the riveting tool not onlyadvances axially under press head pressure against the surface of therivet shank, but simultaneously rotates in an orbital path which canbest be described as parallel to the wall contacts the material beingdeformed, while axially advancing, along a radius line generating fromthe axis of the tool. With constant pressure being applied along thisline, a so-called wave of material is formed ahead of the orbiting toolas it advances and the material being displaced is caused to flow bothradially out wardly and axially forwardly, in this instance toward theflange 40 of the bolt. The riveting tool rotates at a speed on the orderof 1,700 RPM but only a minute quantity of material is displaced pertool revolution. Ergo, minimum friction is created and there is nomaterial tearing or fracturing in that the metal being displaced hassufficient time to properly flow. There is no measurable change in themolecular structure of the material as the result of its deformationfrom initial to final form and the strength of the ultimate form isequal to the maximum strength exhibited by the metal prior todeformation. By utilization of the orbital heading process the materialof the rivet shank 38 is caused to flow radially outwardly to overliethe upper surface of the cross plate and generate the requisite axialtension to draw the retainer components into a securely clampedassembly. Portions of the displaced material are also forced to flowaxially into the cross plate aperture 28 and around the internal wallsof the cross plate defining said aperture so that the length of the boltshank lying within said walls is in effect deformed into and assumes acorresonding hexagonal cross sectional shape, completely fills the crossplate aperture and aggressively engages the walls thereof. Since, asaforesaid, this filling of the cross plate aperture and transformationof the cross sectional configuration of the shank portion disposedwithin the aperture is accomplished without tearing or fracturing themetal, a coupling which provides exceptional strength and resistance torelative bolt to cross plate rotation results. Additionally, theformation of the bolt head 58 by the even, radial metal flow processcoupled with the extensive support or bearing area beneath the crossplate provided by the shoulder 42 or flange 40 provides a furtherimprovement in the retainer coupling from the standpoint of resistanceto axial separation of components.

The above described coupling and particularly the transformation of thecross sectional configuration of the shank portion and the aggressiveengagement of the internal cross plate walls by said transformed shanksection can be clearly discerned from a consideration of the cutawayview of the preferred embodiment of the invention depicted in FIG. 6.

It is also clearly evident from the foregoing descrip tion of thecomponent assembly process that the assembly can be carried out in asingle operation at a single work station regardless of whether thesealing ring is to be included in the retainer combination. It isfurther evident that heat treatment of the cross plate to strengthensame can be completed prior to component assembly and that a spring armof true temper unaffected by subjection to heat treatment can beutilized in the retainer combination. This capability is particularlyadvantageous with regard to larger size retainers in that the hightemperature heat treatment required to impart the requisite cross platestrength will seriously adversely affect the resiliency of the wirespring arm.

In a typical automotive mass production facility where retainers of thetype contemplated by the invention are utilized, several retainers areusually preinstalled at selected spaced intervals along a molding strip'and the strip is at some later stage in the production cycle placedagainst the exterior'of a vehicle body panel with the bolt shankspassing through appropriately sized and spaced preformed panelapertures. Thereafter, nuts are torqued onto the protruding bolt shanks,utilizing power wrenches. Frequently, the end of the bolt shank isstruck with considerable force as a result of careless misalignment ofthe nut with the bolt shank as the driving tool is brought into positionand energized. In all too many instances the force of this impact issufficient to fracture the staked retaining lugs which arecharacteristic of the prior art bolt to cross plate couplings with theresult that the bolt head is driven against and dents or otherwisedamages the back portion of the molding. Consequently, the molding andfastener must thereafter be replaced at a considerable cost in terms ofwasted production effort and material. Thus, the strength of the bolt tocross plate connection which is characteristic of the present inventionand is directly attributable to the enlarged bearing area at theundersurface of the cross plate provided by flange 40 is seen torepresent a marked improvement in the art. In

' view of that improvement it has been found that the method of couplingthe bolt to the cross plate according to the inventions teachings ishighly desirable for use even with older style retainers of the Bedford,Jr., U.S. Pat. No. 2,709,286 type earlier mentioned, that is a retainerwherein the spring arm is secured to the end of a cross plate by areversely bent tongue. One can readily visualize that in such acombination the shoulder 42 of the bolt flange 40 would bear directlyagainst the undersurface of the cross plate rather than on the loop endof the spring arm. In all other aspects, however, the bolt to crossplate connection and process for effecting same are the same as abovedescribed with regard to the improved embodiment.

Thus, it is to be clearly understood that the foregoing description of apreferred embodiment is to be interpreted only in an illustrative senseand that the scope of the invention is to be determined with referenceto the claims which follow:

I claim:

1. A method of joining the molding engaging cross plate and fastenermember of a molding retainer combinationin an assembly wherein the crossplate and fastener member are non-rotatably coupled to one anothercomprising the steps of: providing the cross plate with a throughopening defined by a polygonal peripheral wall; providing one end of thefastener member with a solid, cylindriform, rivetlike shank extendingalong a limited axial extent of the length of said fastener member andhaving a diameter less than the width of said opening in said crossplate; providing said fastener member with a radially protrudingshoulder means disposed adjacent the axially inner end of said rivetlikeshank and having a width greater than the width of said opening in saidcross plate; seating said rivetlike shank generally centrally in saidcross plate opening such that said shank protrudes outwardly beyond oneside of said cross plate and said shoulder means overlies the other sideof said cross plate; displacing material of the protruding end of saidrivetlike shank by a process commonly known as orbital heading to causea portion of the material of said protruding end to flow both radiallyoutwardly and axially inwardly whereby certain portions of saiddisplaced material flow toward said shoulder means and into the withsaid shoulder means, inhibits relative axial movement of said fastenermember and said cross plate.

2. A method according to claim 1 wherein a sealer member is assembledwith said fastener member prior to the displacing of the material ofsaid rivetlike shank.

1. A method of joining the molding engaging cross plate and fastenermember of a molding retainer combination in an assembly wherein thecross plate and fastener member are non-rotatably coupled to one anothercomprising the steps of: providing the cross plate with a throughopening defined by a polygonal peripheral wall; providing one end of thefastener member with a solid, cylindriform, rivetlike shank extendingalong a limited axial extent of the length of said fastener member andhaving a diameter less than the width of said opening in said crossplate; providing said fastener member with a radially protrudingshoulder means disposed adjacent the axially inner end of said rivetlikeshank and having a width greater than the width of said opening in saidcross plate; seating said rivetlike shank generally centrally in saidcross plate opening such that said shank protrudes outwardly beyond oneside of said cross plate and said shoulder means overlies the other sideof said cross plate; displacing material of the protruding end of saidrivetlike shank by a process commonly known as orbital heading to causea portion of the material of said protruding end to flow both radiallyoutwardly and axially inwardly whereby certain portions of saiddisplaced material flow toward said shoulder means and into the spacebetween the outer wall of the remainder of said rivetlike shank and thewall of said cross plate defining said opening therein to nonrotatablylock the fastener member to the cross plate, and other portions of saidmaterial flow radially outwardly to overlie the side of said cross plateremote from said shoulder means to provide a fastener member head which,cooperatively with said shoulder means, inhibits relative axial movementof said fastener member and said cross plate.
 2. A method according toclaim 1 wherein a sealer member is assembled with said fastener memberprior to the displacing of the material of said rivetlike shank.